Electric switch



Sept. 15, 1925. 1,554,048

'6. B. THOMAS ELECTRIC SWITCH Filed April 13. 1922 INVENTOR, 650/755 5. THOMAS -A TTORNEYS' Patented Sept. 15, 1925.

. r 1,554,048 PATENT OFFICE.

GEORGE B. THOMAS, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE BRYANT ELEC- TRIC COMPANY, OF BRIDGEPOR'I, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ELECTRIC SWITCH. 7

Application and Aprfl'18,-18 22. Serial mi. 552,228.

To all whom it may concern:

Be it known that I, Grouse B. Tnoira's,

a citizen'of the United 'States of America. residing at Bridgeport, iii -the cbuntv ot' Fairfield and State of Connecticut, have invented certain new and useful Improve ments in Electric Switches, of which the following is a specification. My invention relates to electric switches,

l and particularly to an electric switch of the key operated type. The object of my invention is to provide a key operatedswitch of such character that. the key cannot beremoved except in predetermined circuit conditions. The switch. is especially useful in a, signal system, but may be employed in any suitable installation.

In theaccompun'ying drawings Fig. 1 is a plan view of a. face plate and associated bulls eye which may. be used with the switchin a signal circuit;

.Fig. 2 is a broken plan of a fitting in which a switch of the present. type is cmbodied; 1

Fig. 3 is a longitudinal section on the line 3-3, Fig. 1; i

Fig. 4 is a dropped perspective of portion of the switch spindle and associated elements;

Fig. 5 is a'mid section .through the key operated barrel; and

Fig. 6 is a plan of the ratchet yoke.

lVhile the present switch may he .arranged in any suitable type of fitting. I have shown it in a signal switch suitable for use in a hotel or'thc like. The s itch is of the flush type and has an associated cover plate 7 which carries a bullsfleye-S, and is slotted at 9 to form a guidcutay for the shank of the switch operating ltcy 10. Beneath the face plate is a cup-shaped insulating body 11, supported by lugs 12 and 13 within an outlet box. not shown), in the customary manner. 14 to accommodate socket terminals 15 and 16 for a pilot lamp 17, housed within the bulls eye 8. The base. is also recessed atlS to afford a switch chamber within which may be arranged a rotary snap switch of any suitable character. That here shown is of a two-blade. type, with a central spindle 19 carrying a crown 20, with which is cingaged one end of the switch spring 21 for rotating the. switch blades 22 and 23 with a snap action. An escapement of any suit- The base is recessed at I able sort may be emplo edjgniy intention does not relate to this eature of the constructlon. Appropriate wire ter1uinals24,

corinected with the switch and socket;tcrminals that in the on position of the switch, a ircuit is established tlirough the pilot la pi and associated signal system.

To-a tuate the switch, I provide a key operatedbarrel 27 slotted at 28 to receive 25 and 26 are mounted on the base undso.

the web 29 formed at the outer end of the .spindle 19. At its opposite end the barrel is slotted at 30 tov receive the engaging firt gers' 31 of the key 10. It is also centrnll recessed at this end to accommodate a guard bushing 32, slotted at 33 to receive themid portion of the key and having a flange 34 which overlies the slots 30 in the barrel. The. neck. of- .the bushing is peripherally channelled at 35 to-receive a detaining pin or new 36 which passes through the outer endIof the barrel and secures the bushing in stvivelling engagement there\rvith. Surrounding the barrel is a.r atchet disc 37, the inwardly extending lugs 38 of which enter the key slots 30 in the barrel and thus entrally apertured at 42'to pass over the barreland' rest against the ratchet 47, which is thus maintained in position, while the same means hold the barrel inengagement with the spindle. Pivoted at 43 on the lowor face of the yoke is a pawl 44 pressed by v the spring 45 against the teeth of the ratchet (115C 37, and thus preventing rotation of the barrel in one direction.

. The shank of the. key 10 is slotted at 46' to straddle the faceplate 7 during the retiition of the key after its insertion in the s 0t 9.

lows: Assuming the slot 33 in the guard bushing to be in register with the slot 30 in the barrel'27, and both to be in register with the slot 9 in the face plate, the key 10 may be inserted through the latter sufiiciently far to bring its fingers 31'into the notches" 30 at the outer end of the barrel,.while the marginal slots 46 in the key register with the face plate 7. The key may now be rotated. and with it the barrel 27 and spin dle19, thus actuating the switch. Assuming The operation of the switch is as folbackward vented by'the pawl 44* engaging the ratchet disc 37 with the barrel 27. If the switch' is now in circuit closing of the key,

slight additional rotation of thekey position, the lamp 17 in thebulls' eye 8 is lighted, and the'associated signal circuit energized. Before thekey mn'be withdrawn it must be further rotated in thesamejdirection, as indicated by the arrow X in Fig. 1. A partial further rotation of the key to the position indicated in dotted lines actuates the switch mechanism to throw theswitch blades to, open'cirouit position. Itis obvious that in this position the key still can n0t be withdrawn, since the face plate 7 is still engaged in the ma a1, notches 46 in the sides of the key Further rotation however, brings the slot 33 in the guard bushing, the slot. 33 in the barrel, and the key itself into register with the slot 9 in the faceplate so .that'the key may now be withdrawn. Inasmuch as the partial rotation places the switch spring 21 under tension, it is obvious that were it not for'the ratchet and awl,'upon withdrawal of the ke the spindle 19 would be reversely rotated and with it the barrel 2?, thus shifting the slot 30 in the latter out of register with the slot 9 in the.face plate, so that the key could not be again inserted. The pawl 44, however, engages the ratchet disc 37 fast on the barrel 27 and thus holds the latter in the position to which it has been switch spring remains under tension and the escapement mechanism of the switch partially. but not fully actuated. Only a to the osition shown in full lines in Fig. l is necgssary therefore .to again closethe circuit through the switch.

In a hotel installation such as 511' gested, a chamber maid entering a,room for service, turns the switch by means of the key t0 circuit closing position, thus closing the signal circuit and also lighting the ulls eye so that the supervising matron may know in what room lie-can be found. As the maid leaves t e room, and the key is turned to position for withdrawal, the circuit is broken and is left in'open-circuit position.

Various modifications in tails of construction and operation will readily occur to those dealing with the problem, without tion.

I claim-- 1. In an electric switch, a rotary switch bar, a spring for driving the latter, an escapement mechanism controlling the rotation of the bar by the spring, a rotary memposition indicated in .fullqth cause the switch to rotated, while the atively 'eparting from what I claim as my invenher for stressing the spring and. operatin e escapement, and means for holding said rotary member against reverse rotation after partial stressing of the spring but in advance of the release ofthe escapement.

2. In an electric switch, a rotary switch bar, a spring for driving the latter, an escapement mechanism controlling the rotation of the bar by the spring, a rotary memher for; stressing the spring and operating the escapement, and ratchet means .for holding the rotary member against reverse rotation after partial stress' g of the spring but in advance of the release of the escapement. 3. In an elwtric switch, a switch-actuating member having a predetermined throw to ating said member, a guard late thro h which the key can pass 0 y when iin switch-actuating member is in anintermediate position, and means for maintaining said member in its intermediate position for insertion or withdrawal of the operating key through the guard P 2 v 4. In an electric switch, a switch-actuating member having a glizdetermined .throw' to cause the switch to ction, a key for operatin said member,-a guardlate through whic the key can pass 0 y when the switch-actuating member is in an intermediate position, a spring tending to maintain said member at the end of its throw, and

means for holding said member in its intermediate position-against the action of said spring to permit the insertion or withdrawal of the operating key through the guard P m a 5. In an electric switch, a rotary switch spindle, a rotary switch bar, a spring 0 roonnecting the spindle andswitch bar. and escapement operated by the spindle and controlling the rotation of the switch bar, a for o eratively en a ing the switch siiiii dle, a g ard plate thr ugh which the key passes into said operative engagement with the switch spindle, and a kefyway member beneath the guard plate, t e key-ways in said guard plate and key-way member registering only in a position in which the spring is under stress and the escapement partially withdrawn. together with means for maintaining said parts in register to permit the introduction or withdrawal of the spindle-operating key.

5. In a rotary snap switch, a rotary switch spindle having an associated key way a guard plate having a key way registering with the spindle keyway only in certain pgsition of the latter, and a member swivelli g with respect to the spindle and having a key way adapted to register with that 1n the spindle and guard plate in a certain position of the parts. andhaving means toob; structuwcess to the key way in the spindle in other relative rotary positions.

function, a key for oper-' 7. In a rotary snap switch, a rotary spindle, a key-operated barrel adapted to engage said spindle for'rotation therewith, a ratchet iii'em ber fast with said barrel, a switch spring stressed by the rotation of said spindie, means engagmg'said barrel to hold it in position on the switch spindle, and an associated ratchet switch member carried by said holding means to prevent reverse rotation of said spindle.

8. In a'r'vtary sna switch, a key-operated rotary switch spin 1e, a cover plate overlying the same and apertured to permit the engagement androtation of the key with the spindle, and aJnember swivelling with respect to the spindle and located at the aperture in the cover plate to prevent access to the key wa in the spindle except in pre determined relative position of the movable parts with respect to each other and to the cover plate.

9. In a rotary snap switch, a switch spindie, a key way member engaged at one end of said spindle to rotate therewith, a ratchet on said member, a stationary frame element holding said member in position, and a pawl on said frame element and engaging said ratchet to prevent reverse rotation of said spindle after partial rotation thereof in switch-operating direction.

In testimony whereof I have signed my name to this specification.

GEORGE B, THOMAS. 

